As a software developer, I'm writing to benefit me because I use the code I write.
What I write and share is directly re-usable to others.
We can walk a path and share our work, and others can take it and copy it immediately.
Whereas with UX.. Most of the time it's written for the benefit of someone else. And it's not something that can be used elsewhere very easily.. Often needing to be completely re-worked to be useful anywhere else.
You're talking about libraries. And parent answered to message about end user software. Sure, you might use your own end user software, but so can UX designer.
If the designer isn't also a software developer who writes a new application to scratch their UX itch, then they must work with some existing project, which presumably has existing users..
It's probably always going to be harder to contribute design overhauls than bugfixes & features.
What I write and share is directly re-usable to others.
We can walk a path and share our work, and others can take it and copy it immediately.
Whereas with UX.. Most of the time it's written for the benefit of someone else. And it's not something that can be used elsewhere very easily.. Often needing to be completely re-worked to be useful anywhere else.